The Estimation of Cathepsin With Hemoglobin and the Partial Purification of Cathepsin

Abstract

An account of previous work on cathepsin may be found in the monograph of Pozzi (1935).In the hemoglobin method for the estimation of protelnase, denatured hemoglobin is digested and the digestion products not precipitable by trichloracefic acid are estimated colorimetrically. Hemoglobin, unlike commercial casein, edestin, and gelatin, is a reproducible substrate, Only the very first stages of digestion are measured by the tfichloracetic acid method, for only a small amount of digestion is needed to make hemoglobin not precipitable by trichloracetic acid. Thus, only true proteinase is estimated by the hemoglobin method.Almost all the estimations of proteinase recorded in the literature have been made with substrates that are not reproducible. As a result, the values of proteinase activity obtained in different laboratories, or in the same laboratory with different batches of substrate, are not quantitatively comparable. Furthermore, most of the values of proteinase activity recorded, in particular those obtained by the Willst~tter school, were obtained by methods which estimate not proteinase activity alone but the activity of proteinase plus other proteolytic enzymes. As a result, the values obtained by different investigators are not even qualitatively comparable. The hemoglobin-trichloracetic acid method estimates proteinase alone, yields reproducible results, and has now been applied to the four known types of proteinase, pepsin (Anson and Mirsky (1932-33)), trypsin (Anson and Mirsky (1933-34)), papain (Anson (1936-37)), and cathepsin. It would seem desirable that if some other method is used, either independent evidence be given that the method estimates proteinase 565

Inhibition of long-acting thyroid stimulator by thyroid particulate fractions.

“…Cathepsin (acid protease) in tissue fractions was assayed by incubation at 370 C for 30 minutes with a hemoglobin substrate in 0.2 N acetic acid (9). Acid phosphatase was measured with CalSuls; 2 i8-glucuronidase activity was measured with a phenolphthalein glucuronide substrates (10).…”

CONCENTRATION OF ACID PHOSPHATASE, RIBONUCLEASE, DESOXYRIBONUCLEASE, SS-Glucuronidase, AND CATHEPSIN IN "DROPLETS" ISOLATED FROM THE KIDNEY CELLS OF NORMAL RATS

“…In the present assays, the concentration of the substrate was reduced 5 times, resulting in normal color development within 10 minutes. Cathepsin was determined according to Auson's hemoglobin method (10). The samples were incubated for 30 minutes at 37 ° in acetate buffer, pI-I 4.0.…”

“…The samples were incubated for 30 minutes at 37 ° in acetate buffer, pI-I 4.0. Tyrosine served as reference for cathepsin units (10), and the results were expressed in mill/equivalents of tyrosine per milligram N per minute X 104.…”

Social stress in laboratory rats Rattus norvegicus results in decreased immune competence of the offspring

“…Results of these two tests were expressed as a count per minute (cpm) for 1 ml of the sample or for 1 mg of the protein, respectively. (4) Cathepsin D activity was determined by the Anson's test (Anson 1936). The activity of cathepsin D in macrophages and serum was expressed as a quantity of tyrosine (mg) produced by cathepsin D during an hour per 1 mg of the protein.…”